Five reasons to promote OCC

The light spectrum is a rescue solution for the exponential growth of wireless connectivity demand. The bandwidth of light is 1000 times larger than the entire RF bandwidth. Among light communication technologies, Optical Camera Communication (OCC) is an entirely software-based solution, which is the best compatible with existing infrastructures such as commercial cameras and lighting. …

A-QL Code Update available

We now release an update of the A-QL Code by adding several interesting features: Switching between 16*16 and 32*32 cells modesAuto-threshold feature for RXEnable button for option of RGB colors calibrationFeedback nodes for a clean block diagram Please download the following PPT file for a review of the software User Interface (TX and RX). A-QL …

Update OpenSource List

The OpticalPress Team is happy to provide Open Source Codes based on IEEE 802.15.7-2018 Optical Wireless Communication (OWC) standard, the most recent international standard that includes Optical Camera Communication (OCC) technologies. We believe that the codes are beneficial for the implementation of your novel ideas as well as practical comparison purposes. We were lucky and …

Implementation of HA-QL Code

HA-QL (Hidden Asynchronous Quick-Link) is a hidden modulation mode among Screen-2-Camera operating modes within the IEEE 802.15.7-2018 Optical Wireless Communication standard. An interesting feature of HA-QL is that it allows for controlling the peak-to-peak amplitude of the intensity modulation, from a visible code to a hidden code. The HA-QL Code Project is cleaned, well-packed and documented. Technical …

(PPT) BER measurement of A-QL

A-QL stands for Asynchronous Quick Link, a two-dimensional multi-band color code sequential transmission protocol from a screen to camera. The A-QL is one of mode within the IEEE 802.15.7-2018 Optical Wireless Communication standard. For your convenience, we have measured the BER performance of A-QL code. The results showed that A-QL can support the transmission distance of 4.5m with the wide …

Performance of Screen OCC: 2D-OFDM vs. A-QL

In the previous posts, the implementation demo and the implementation guidance of the Screen-OFDM system were shown. The measured performance comparison between Screen-OFDM and a traditional A-QL in IEEE 802.15.7m is reported in this post. Overview of 2D-OFDM vs A-QL A-QL is the single-carrier modulation while 2D-OFDM is the multi-carrier modulation approach applied for the …

Needs for OCC: Line code, Scrambler, Interleaving, and CRC

This post discusses several aspects of light communication as follows Line Coding: What and Why Line Coding is needed? Other choices? Scrambler: What is a Scrambler? OCC needs this? Interleaving: Purpose and Generation. Cyclic Redundancy Check: Where it is applied.   Run-length limited code for Visible Light Communication According to Wikipedia, for reliable clock recovery …

Customizing MAC for OCC Modes

This post discusses the topic related to OCC MAC and MPDU.   IEEE 802.15.7m OCC MAC Layer "Use of over-the-air MAC frame configuration is forbidden for PHY types IV, V and VI. It is mandatory MAC frame configuration be done via the MAC PIB. This is due to the fact that unlike traditional wireless LAN/PAN, the data …

Software-defined Configuration method for OCC Systems

The purpose of the post is to specify the PIB attributes for configuring a particular OCC PHY mode. Any OCC PHY mode is co-existing with the others and recognizable by a specific receiver once the PIBs are specified. The configuration of PHY-PIB attributes is software-defined (App-based). Without using PHY-frame overhead, the App-based configuration is communication …

PPDU: PHY frame format for Screen Modulation Systems (A-QL & HA-QL)

This post reviews the design of the Physical-layer Packet Data Unit (PPDU) for A-QL and HA-QL operating modes within PHY IV Screen modulation of IEEE 802.15.7m. For implementation, the Data Frame Format is crucial; each operating mode has its packet format and the format specification has its reason. At least, time is spent on optimizing …

HA-QL: Part 2 – Hiding data into Screen using Wavelet Transform

HA-QL (Hidden Asynchronous Quick-Link) is a hidden modulation mode among Screen-2-Camera operating modes those are being standardized at IEEE 802.15.7m. The previous post explains the principle to generate a hidden code on the screen using an additional intensity modulator after the bit-intensity mapper. However, the modulation of screen intensity dramatically degrades the communication performance. In …

HA-QL: Part 1- Intensity modulation for Hidden Screen Code

HA-QL (Hidden Asynchronous Quick-Link) is a hidden modulation mode among Screen-2-Camera operating modes those are being standardized at IEEE 802.15.7m. This post describes what it is for and how it operates. Introduction The name Hidden A-QL briefly describes how it operates. The mapping from bits into the screen cells during modulation in HA-QL shall follow …

A-QL: Part 2 -BER Measurement

A-QL (Asynchronous Quick-Link) is a Screen-2-Camera operating mode being standardized at the IEEE 802.15.7m. This post introduces the BER measurement method and the performance of A-QL system. See this video demo for the BER measurement scenario: https://www.youtube.com/watch?v=Mkq2lYKzQsQ   Experimental Setup The scenario for measuring BER is illustrated in Figure 1. The bit rate is measured …

A-QL: Part 1- Introduction of Reliable Screen-Camera Communication

A-QL (Asynchronous Quick-Link) is a Screen-2-Camera operating mode being standardized at IEEE 802.15.7m. This post describes what it is for and how it operates. Figure 1 - Example of color code displaying with video on a screen And before we start talking about A-QL system, a short demo of it is here: https://www.youtube.com/watch?v=B6uBTSdh44Y Introduction The …

PHY modes within IEEE 802.15.7m draft – a quick review

PHY operating modes  The latest IEEE 802.15.7m draft standard (until Aug. 2018) is on the Sponsor Balloting recirculation. This version has updated a lot in compared to the previous version before LiFi modes are moved to new task group under IEEE 802.15. A list of operating modes between two drafts is a good start. Notation …